#include <stdio.h> 
int main()
{
    int a;
    printf("Please enter an integer: ");
    if (scanf("%d", &a) != 1)
    {
        printf("Invalid input! Please enter an integer.\n");
        return 1; 
    }
    printf("The integer you entered is: %d\n", a);
    return 0; // 程序正常结束，返回0
}